8941/8945 Firmware Upgrades

Got the lab 8945 out of the cupboard today to register it to a CUCM 10.5 server, unfortunately it kept seizing up during the firmware upgrade - the display would show "upgrade in progress" & the phone is totally unresponsive. Turns out you can't upgrade 8941/8945 phones to firmware version 9.4(1) or later unless you're running 9.3(4). The firmware release notes do actually state this important fact, so remember always read the release notes when upgrading phone firmware!